Musical signal device



Dec. 25, 1945. I A. c. GRoHsGAL 2,391,698

MUS ICAL S IGNAL DEVI CE fz# INVENTOR. 4J lzzfff @ra/2.11510! Dec. 25,12945. A. c. GRoHsGAL 2,391,698

MUSICAL SIGNAL DEVICE Filed April 24, 1940 3 Shees--Shee'l'I 2 4&1701

1NVENTOR. l

Dec. 25, 1945. A. c. GRoHsGAL MUSICAL SIGNAL DEVICE Filed April 24, 19403 SheebS--Sheel 3 /vio ATTORNEYS Patented Dec. 25, i945 MUSICAL SIGNALvDEVICE yAlexis C. Grohsgal, New York, N. Y.,

assignor to Marks Products Co. Inc., Brooklyn, N. Y., a corporation ofNew York Application April 24, 1940, zSerial No. :331,332

g 4 Claims.

This invention relates to improvements in electric musical signaldevices and more particularly to improvements in devices of theforegoing character utilizing vibratable elements for pro-- ducingmusical notes.

An object of the present invention is to provide a new, simple,efficient musical signal device which is inexpensive to manufacture andwhich can be assembled with a minimum of llabor.

Another object of the invention is to provide a device of the foregoingcharacter in which the vibratile element is of substantially lU-shape incross section.

Another object of the invention is to provide a signa-l device whereinthe vibratile element is of such character that it can be fastened to asup porting member at any point or points within a relatively wide areawithout interfering with the vibrating properties thereof.

`Another object of the invention is to provide a casing wherein all ofthe operating vparts of a signal device can be mounted, which casing isadapted to Abe enclosed by a plain back plate.

A further object of the invention is to provide a casing, preferably ofmolded material, such casing being so constructed as to lrequire aminimum of assembly parts for securing the operating portions of the`device Within the casing.

An additional object of the invention is to provide a signal devicewherein two vibra-tile elements can be set in vibration simultaneouslyby a single actuating member.

A still further object of the invention is to provide a signal device inwhich the vibratile element is of such character that it can be mountedwithin the enclosing casing in any of several different positionswithout affecting 'its vibra-ting characteristics.

In carrying out the foregoing and other objects `of the invention, useis vmade in all forms thereof of a vibrating element or elements whichare of substantially U-shape in cross section whereby such elementacquires 'to some degree the characteristics of a tuning fork. Due tothis shape of the element, it is possible to attach the same to asupporting casing or mou-nt by means of a plate member which can besecured to the vibrating element at any of a number of points within avery Wide range, which range is present along the loop portion of theelement.

In 4one form of the invention, use is made of a housing, preferablymadeof some suitable molded material such as a Aphenol condensation productor any of the well-known plastic materials, which housing is shaped vtohave side wal1s,'top

and lbottom walls anda front Wall, all formed as integral parts of thecasing. A back plate of suitable material which may be similar to rthatof the housing or any material serves to close the back of the housingto better the acoustics of the device and to shield 'operating partsfrom -a Wall or other supporting structure to which thchousing may besecured. The housing has a plurality of openings therein which arepositioned adjacent the vi-bratile element mounted therein. This elementas before mentioned, is of substantially U-shape in cross section and isfastened within the housing by means of a plate or strip attached to theelement in the loop portion thereof in any suitable fashion. Alsomounted within the housing is an electric solenoid or other suitableactuating device which has associated therewith a striker capable ofbeing actuated to strike the vibratile element thereby to cause it toproduce a musical note. The solenoid or other actuating mechanism ismounted on integral parts of the housing and retained therein byresilient formations formed on a part of the yactuating mechanismsupport. A device so made is suitable for producing a single musicalnote when the vibrating element is struck by the actuating striker.

If desired, a similar housing can be utilized for mechanism which canproduce a double muslcal note. 'In this event, two vibrating elementsare mounted end to end Within the housing with their adjacent endsslightly separated. They can be secured to the housing by a singlesupport member or if desired *by duplicate members. Due to the closeproximity of the ends oi these vibrating elements, a single striker ofsuitable size can be utilized for striking the end portions of the twoelements simultaneously thereby causing vibration thereof; and if theelements are differently tuned, producing a double musical note.

In another form .of the invention, two vibrating elements of the typedescribed caribe mounted at opposite ends .of a housing and again asingle actuating member or Vmechanism utilized for :starting vibrationof these :elements in sequence. For this purpose, the core vof asolenoid is provided with strikers ,at each end thereof so that Aupon.energization of the solenoid, movement of the plunger `causes thestriker at one Vend. thereof lto vibrate yone of the elements Whilereturn movement of the plunger causes the striker at the 'other end'thereof 4to vibrate the second element. Means are provided in thisarrangement for Vmaintaining Ithe strikers normally vout of contact witheach element and also Vfor returning the strikers, after a cycle ofoperation, to theirV normal positions.

In a still further form of the invention, vibrating elements can bemounted as disclosed with reference to the last mentioned embodiment butinstead of using a single actuating device, use may be made of twoactuating devices. In this form of the invention, one actuating devicewill have two strikers arranged as before described and in addition, thesecond actuating device will have a single striker thereon so that whenthis second striker isactuated, a single musical note will be producedas distinguished from two musical notes in sequence with thedoublestriker actuator.

The vibrating element or elements may be mounted within a casing in anyof a number of positions such as with the loop thereof directed towardthe open rear of the housing; with the loop directed toward the frontwall of the housing; with the loop directed toward the Vtop of thehousing; or toward the bottom of the housing. In any of thesearrangements, a suitable striking mechanism can be employed and suchmechanism may be mounted at any convenient point within the housing,since the vibrating element or elements possess the characteristic thatthey will vibrate to produce the desired musical note regardless of thepoint at which the striker contacts either leg of the element.

Other features, objects and advantages of the invention will becomeapparent by reference to the following detailed description of theaccompanying' drawings wherein Fig. 1 is a View of the open back of thehousing showing parts of the signal deviceA in position therein;

Fig. 2 is a section taken substantially along the line 2--2 of Fig. 1;

Fig. 3 is a section taken substantiallyn the line 3-3 of Fig. 1;

Fig. 4 is a vertical section through a plain plate-like back member usedto enclose the housing;

Fig. 5 is a fragmentary View similar to Fig. 1 or a modified form of thedevice utilizing two vibratile elements;

Fig. 6 is a fragmentary view showing a second method of securing twovibratile elements within a housing;

Fig. '7 is a view similar to Fig. 1 of a further embodiment of theinvention wherein two vibratile elements are located at opposite ends ofthe housing;

Fig. 8 is a section taken substantially on line 8--8 of Fig. 7;

Fig. 9 is a section taken substantially on the line .9 9 of Fig. 7;

Fig. 10 is a view similar to Figs. 1 and 7 of a still furthermodification of the invention wherein twoactuating devices are used;

Fig. l1 isasection taken substantially on the line H-H of Fig. 10, and

Figs. l2 to 15, inclusive, are diagrammatic showings of variouspositions in which vibrating elements can be mounted in a housing.

Referring to the drawings and particularly Figs. l to 4, inclusive, il!indicates generally a casing made up of some material which can bereadily 'molded This material may be a phenol condensation product, orany of the well-known plastic materials which lend themselves to readymolding, or any other desired material. The casing ingeneral is made upof a front wall Il, bottom wall I2, top Wall l and side walls l5. Thebottom wall l2 is of shorter expanse than the top wall so that the frontwall is on an incline and the side walls are also inclined. integrallyformed with the bottom wall l2 is a flange portion I6 having an openingI1 therethrough while the top wall has a similar flange portion i3 withan opening i9 therethrough. The front wall Il is provided with aplurality of openings E, the purpose of which will be explained later.Within the casing and formed integrally therewith is a partition member2l and two hollow bosses 22.

Mounted within the top of the casing is a vibratile element 2t formed inany fashion from suitable metal having the proper characteristics toproduce a musical note when subjected to vibration. This element, asshown in Fig. 2, is of substantially U-shape in cross section so thatwhen one leg thereof is subjected to vibration, the other vibrates inharmony therewith, thereby acquiring some of the characteristics of atuning fork.

The element 2:3 is heldin place by a metallic strip 25 shaped as shownto provide the proper clearance. This strip 25 is secured to the casingby an eyelet 26 passing through an opening in the strip and through theopening i9 in theV flange i8. The strip 25 can be secured to the looppart of element 212i in any desired fashion such as by spot welding,riveting or any mechanical equivalent thereof. The exact point ofattachment between the element 2t and the strip 25 can be within a widearea located in said loop part, since due to the character of theelement, it is immaterial whether the attachment be made exactly midwaybetween the ends of the element or at another point therealong. Also theattachment does not necessarily have to be along a geometrically medianline in the loop part but can be offset relative to such'median line toimpart the desired angularity to the element. In this respect, thevibratile element is far superior to flat vibratile elements and thelike heretofore used in the electric musical signal devices, which flatelements must necessarily be mounted at narrowlydefined nodal points. l

Mounted in a yoke member 2l of some suitable metal is a solenoid 2S. Theyoke 21 has two flange portions 29 with through apertures therein andwith separated slightly upturned tongues 30. The minimum diameter of theaperture, as determined by the inner edges of the tongues B, is slightlyless than the maximum diameter of the associable `boss 22 so that theseflanges 2S can be pressed on to the bo-sses; the anges yieldingsufficiently for this purpose, but when the anges are seated against theinner surface of the front wall Il, the tongues 3B effectively preventinadvertent removal thereof. In this manner, elimination of separateattaching parts is accomplished, The yoke 21 has aligned openings 3ltherein for the passage of the'solenoid plunger 32, which plunger hassecured to its upper end, a striker 35. Secured to the bottom wall YI2is a pad 35 of felt or any other suitable cushioning material. This pad35 serves as a rest for the lower end of plunger 32 in its normalposition.

Screw terminal members 3B and 31 are located in the flange part I8 andfrom these terminal members, wires 38 and 39 lead to the solenoid 28.

The top, bottom, and side walls of the casing are so made as to providea continuous wall 46 with a shoulder 4l inwardly located relative to theinner edge of the wall 40. At spaced intervals along the inner surfaceof this wall 40 are slight bumps G2 which terminate short ofthe shoulder4l, A back plate 64 of Vany suitable material such-as fiber, phenolcondensation product, pressed board, a plastic or the like is adapted toilt closely within the wall v40 and be retained therein by engagementunder the bumps 42. This wall 44 has openings 45 therein lwhich can beproperly aligned with the respective openings Il and I9 in the housing,and has other openings registering' With the terminals 36 and 31.

The operation and use of 'the device just described lis substantially asfollows. `Conductors connected with a suitable source of energy can beconnected to the terminals 36 and '31. The entire -device `then can bemounted on a suitable supporting surface 'such as a wall or the like byscrews passing through the opening Il land through the Aeyelet 26. Whenso assembled, the solenoid '28 can be energized by `closing of fa properswitch, upon which energization the plunger 3'2 is moved upwardlyrapidly causing the striker v34 to strike the lower leg of thevibratil-e element lill. Vibration is immediately set up vof both legsof the element producing -a musical note `within the casing, which initself acts as a sound chamber. The openings 20 permit the soundvibrations to pass efficiently from the casing without any appreciableclamping effect. The impact between the end of the striker 34 and theelement 24 is momentary, after which the plunger 32 drops downwardly,due to the force of gravity and eventually returns to its normalposition as shown in Fig. '2 `with end thereof resting on the pad 35.Repeated closing of the energizing circuit will cause repeated vibrationof the element 2'4 thereby causing the device to act as a musicalsignal.

In the embodiment shown in Fig. 5, a slight variation from that shown inFigs. 1 to 4 has been accomplished. In the latter modification, thehousing is constructed in a similar manner and the actuating mechanism,namely the solenoid, is secured in the same fashion as before described.Accordingly, similar parts have been given similar reference characters.However, the striker 34 of Fig. 5 is of larger diameter than the striker34. Likewise, vthe metallic strip 25', instead of having parallel sideedges, is more or less a forked member having spaced end portions 50. Tothese end portions are secured two vibratile elements Zia and 24h, theends of which are spaced apa-rb an amount suiiicient to prevent contactbetween the elements even under the most severe vibration. The end parts50 of the strip 25' can be secured `to the elements .by spot welding,riveting `or any equivalent arrangement. Due to the positioning of theelements 24a and 24h, with their ends in close lproximity and also dueto the increased diameter of the striker 34', it is possible, wh'en thesolenoid of Fig. 5 operates to elevate plunger 32, for the striker 34'to strike the two vibratile elements simultaneously. If these elementsare constructed to have different musical tones, it follows thatactuation of the solenoid will set the two elements vibrating at theirrespective tones thereby producing a double note which can be blended.Again vwe find that the element of the 'present invention makes possiblethis simple production of a blended double note due to the .fact 'thatvthe elements can be contacted by a striker at almost any point in a legpart thereof. The elements 'also can be secured to the `casing by asingle attaching strip which can be fastened to the elements at anypoint in the loop parts thereof within reasonable ranges. Thisconstruction obviously possesses considerable merit and advantages overprior constructions approaching similar results.

Fig. 6 illustrates in fragmentary fashion a slightly differentarrangement for Vsecuring two elements '24a and 241i in position withinthe casing, such arrangement consisting of a strip 25a similar to strip25 .of Fig. 2 with. the exception that this strip is split as at 5| toproduce two separated end parts 52. These end parts can be spot weldedor otherwise secured to adjacent end portions of the vibratile elements24a and 24h. This `construction is shown simply to demonstrate theversatility of the elements of this invention in that they can befastened in vthe casing by attaching means which is not necessarilysecured tothe elements at any midpoint thereof.

'Referring now to the form shown in Figs. 7 to 9 inclusive, a casingindicated generally at 'l0 is constructed substantially in the samefashion as the casing of Figs. 1 and 2 with the exception that the topand bottom walls are of the same length. VIn this form, the casing 'I0is made up of a front wall 1|, top wall 12, bottom 14, and side walls'15. Within the casing, partitions 1.6 are provided spaced from the topand bottom walls. Likewise, a plurality of openings 'l1 and I8 areformed in the front wall adjacent the top and bottom walls and betweenthese walls and the partition 16. Hollow bosses 'I9 are formedintegrally with the front wall as well as a platform 8l] having two gaps8| and 82 therein. An upper vibratile element 84 is fastened to thehousing by a strip 85 and eyelet 8B in the same manner as the element 24of Figs. 1 and 2. In

" addition, a second vibratile element 81 is secured within the casingnear the bottom thereof by a member `88 and eyelet 89 in the samefashion as the upper element. A solenoid 90 is held in assembly by yoke9| having anges 92 secured to the bosses 19 in the manner beforedescribed.

The solenoid Sil has a plunger 94, to the upper end of which is secureda striker and to the lower end of which plunger is secured a striker 96.This latter striker passes through the gap 8| in the platform 80 and hasa spring 91 encircling the same above the platform and resting on awasher 98 extending across the gap 8|. The spring is of such size andstrength as to maintain the plunger normally in the position shown inFigs. '7 and 8 `wherein the bottom of the striker Q6 is held elevated aslight distance above the top leg of the element 3l. A back plate notshown, similar to the plate 44, is held in assembly with the casing inthe same manner as before described, namely by bumps 99 formed in theinner wall of the casing boundary edge.

Screw terminals Iil and |0| are provided for the attachment ofconductors leading to a suitable source of energization anda conductor|02 fastened to terminal |00 is connected to the solenoid 9u while asimilar conductor |04 connects the solenoid with the terminal l0 I Theoperation of this embodiment of the invention is substantially asfollows. When the solenoid is deenergized, its plunger is in the normalposition shown in Figs. 7 and 8. yWhen a circuit is closed lto energizethe solenoid, the plunger is moved upwardly with 4sufficient force tocause the striker 95 to strike the upper element 84 causing it tovibrate and produce a, musical note. When the plunger rebounds, it willfall due to gravity, and on account'of its weight it will descend untilthe lower striker 96 strikes the lower element 87 causing it to vibrateand produce a musical note. In each instance the contact between the`respective strikers and elements is momentary so that the vibration ofthe elements is not impaired. In the instance of the lower element, thespring 91 serves to restore the plunger to its normal position after thelower striker has contacted the lower element, the spring 91 being weakenough to permit gravity to accomplish such contact bediffer fromthatpreviously described in that instead of a single solenoid 98, use ismade of two solenoids IZB and |2| in side-by-side relation andsup-ported -by a yoke indicated generally at |22, which yoke hashorizontal portions |24 of increased longitudinal length to support thetwo solenoids. The yoke has the same flanges 92 utilized to secure it tothe bosses 79. The solenoid |29 has a plunger |25 provided with astriker |26. The lower end of plunger |25 normally rests on a pad |27 offelt or other sound deadening material, which pad is located on the topof the platform 83. The other solenoid |2| is identical in construction,in all of its essential parts with the solenoid 9|) of Figs. 'l and 8but the lower striker 9S, instead of passing through the gap 8| inplatform 8|), passes through the gap 82.

A conductor |30 connects the screw terminal |00 with one terminal of thesolenoid |20. The second conductor 13| connects this same terminal ldwith the solenoid |2|. A third conductor |34 connects the terminal ||l|with the solenoid |2 while a fourth conductor |35 connects the terminal||l with the solenoid |2|. Suitable channels are provided in the moldedhousing for keeping the conductors |34 and |35 separated. It will beapparent therefore, that the terminallll serves as a common terminal forboth solenoids while the terminals lill and l@ serve the individualsolenoids.

The operation of this embodiment of the invention is substantially asfollows. Assume that the terminal I is connected to one side of a sourceof energization, then the terminals |8| and IIE! will Ibe connectedthrough diierent switches to the other side of the source. Thus, whenthe switch associated with terminal ||l| is closed, the solenoid `|2|]is energized, causing striker l' to contact upper element 84, therebyproducing a musical note as the result of its vibration. If the switchassociated with the terminal lo is closed, then solenoid |2| isenergized, causing a sequential striking of the upper and lower elements84 and 81, thereby producing two musical notes in sequence andordinarily, as in the case of the embodiment of Figs. 7 to 9, these twoelements will be tuned to different tones so that the sequential notesare different. This embodiment of the invention is particularly usefulfor household purposes wherein switches are provided at two doors sothat actuation of one switch causes the production of one musical 'notewhile actuation of the other switch causes the production of two notesin sequence, thereby enabling facile recognition of the particularlocation from which a given signal has originated. 1 In Figs..12 to 15,inclusivayarious positions in which a vibratile element can be mountedin va casing have been illustrated diagrammatically. Fig. 12 showsdiagrammatically the position ofV an element in accordance with thefirst embodiment of Figs. 1 to 4 inclusive, and also the upper elementsof the other embodiments.

Fig. 13 shows diagrammatically how the position of such an element canbe reversed.

Fig. 14 shows diagrammatically how an element can have its loop partnear the top ofthe housing while Fig. 15 shows how the element vcan havethe ends oi its leg portions close to the top of a housing. In any ofthe forms shown, suitable supporting devices and suitable strikingarrangements can be used without departing from the scope and spirit ofthe invention. Other angular positions of the elements are possible.

While the invention has been illustrated and described as being soconstructed that the vibratile elements and other operating parts areattached directly to the multi-walled housing, it will be obvious thatany or all of such parts can be attached directly to the back plate.`This plate may be flat or, if desired, may have integral formations forthe attachment of the various` parts in the same manner as illustratedin connection with the 'main part of the housing.

From Ithe foregoing, it will be seen that this invention provides a newsignal device utilizing a new type oi vibratile element for producingmusical notes especially adapted for signal purposes. The elements o-fthe invention possess advantages not `found in elements heretofore used.For example, the vibrantile elements which are of substantially U-shapein cross section, are Vof the utmost compactness and can be made in awide range oi size, all of which are capable of being enclosed within a,comparatively small housing. Due to such compactness, it is notnecessary for any part of any operating elemenlts to extend outside ofthe housing. The vibratile elements also possess the advantage that theycan be sup.- ported or mounted with simplicity, since a single attachingmember is sufficient to mount an element to a supporting structure.Ordinarily, the U -shaped element is attached to some supporting memberat a single point preferably along the median line of the loop part; ofthe element, This point, however, may be at any location along the looppart of the element, consequently eliminating the necessity fordetermining accurately spaced nodal points. Furthermore, a vibratileelement of the character disclosed herein can be secured to a supportingstructure either with a rigid connection or with a resilient connection.Consequently, it follows that the element can be connected directly to asupporting structure such a housing with the loop part thereof inphysical contact with the housing, or it may be connested by means of astrip member as shown herein, which strip member can be resilient ornon-resilient as desired. It is not essential that the elements becontacted by Ya striker at any partisular vpoint since .the impact of astriker on either leg of an element at substantially any point on suchleg, will cause instantaneous vibration of both legs, thereby setting upa musical note determined 'by the tuning of the element.

The U-shaped elements, as shown in the draw-V ings, each have legs thewidths of which are many times the thickness thereof, for the purpose ofcausing the elements to have amplitude or volume of vibration suiilcientfor signal purposes. Inpractice the ratio of width to thickness can bevaried to any desired degree above about 20 to l; the illustratedelements being constructed with a ratio of substantially 55 to 1, butthis ratio is not to be considered a limitation on the invention.

The invention also lends itself to the use of additional resonators asis customary since it is possible, if desired, to include separateresonators usually in the form of cylinders for the purpose ofaccentuating the note produced by a vibratile element. These additionalresonators can be mounted directly within the housing along With thevibratile elements so that again all parts are completely enclosed.

The construction of the device as a whole is novel in that a unitarycasing is adapted to contain all operating parts of the device and suchparts are assembled with the casing with a, minimum of assemblingaccessories such as screws and the like. Consequently, the device lendsitself readily to economical manufacture with a minimum of expense bothas to construction of operating parts and assembly thereof.

In view of the foregoing, it is to be understood that the invention canbe modified beyond the illustrated embodiments and therefore is to belimited only by the scope of the following claims.

What is claimed is:

1. A sustained-signal device of the momentarily-energized resonantannunciator .type described, comprising: a vibratile element consistingof a wide thin strap of metal bent into U- shape dening a pair ofsubstantially parallel leg portions disposed with their inboard faces inspaced opposition and joined by an intermediate bend portion, said legseach having a widthto-thickness ratio of at least 20 to 1, a combinedhousing and resonance box for said vibratile element, a supportingmember for said vibratile element secured to a wall of said combinedhousing and resonance box, attached to said intermediate bend portion ofsaid vibratile element and maintaining the legs thereof well out ofvibratory contact with said combined housing and resonance box, and aquick-acting striker member supported by said housing and relativelymovable with respect thereto for initiating sustained vibration of saidhousing-attached vibratile element by momentary contact therewith.

2. A sustained-signal device of the momentarily-energized resonantannunciator type described, comprising: a vibratile element consistingof a wide thin strap of metal bent into U- shape dening a pair ofsubstantially parallel leg portions disposed with their inboard faces inspaced opposition and joined by an intermediate bend portion, said legseach having a width-t0- thickness ratio of at least 20 to 1, a combinedhousing and resonance box for said vibratile element having a soundopening therein, a supporting member for said vibratile element securedto a wall of said combined housing and resonance box, attached to saidintermediate bend portion of said vibratile element and maintaining thelegs thereof extending toward the sound opening of said combined housingand resonance box in close proximity thereto but non-contact therewith,and a quick-acting striker member supported by said housing andrelatively movable with respect thereto for initiating sustainedvibration of said housing-attached vibratile element by momentarycontact therewith.

3. In a sustained-signal device of the momentarily-energized resonancebox annunciator type described, a vibratile element consisting of a widethin strap of metal bent into U-shape defining a pair of substantiallyparallel leg portions disposed with their broad inboard faces in spacedopposition and joined by an integral intermediate bend portion, saidlegs each having a width of at least 20 times the thickness of the metalstrap of which .they are formed, and means attached to said intermediatebend portion of said strap for supporting s aid vibratile element andmounting same upon the resonance box of the signal device.

4. A sustained-signal device of the momentarily-energized resonantannunciator type described, comprising: a rst vibratile elementconsisting of a wide thin strap of metal bent into U-shape defining apair of substantially parallel leg portions disposed with their inboardfaces in spaced opposition and joined by an intermediate bend portion,said legs each having a width-tothickness ratio of at least 20 to 1, asecond vibratile element of the same, above-defined, structure buthaving a musical pitch different from that of the first vibratileelement, a combined housing and resonance box for both of said vibratileelements, means attached to the intermediate .bend portions of each ofsaid two vibratile elements and mounting same in closely spacedsubstantial parallelism in said combined housing and resonance box, anda quick-acting striker member supported by said housing substantiallysymmetrically of said mounted vibratile elements and effective, whenactuated, to initiate simultaneous vibration of both.

ALEXIS C. GROHSGAL.

